Is iOS 18.5 causing battery drain on my iPhone 15 Pro Max?

Not just iOS 18.5, but about all updates cause this phenomenon. Your iPhone has to re-index all of your data after the update which evidently will work harder and cause the iPhone to drain more battery. Re-indexing is sorting all of your data and content on your iPhone. But your iPhone's battery health should not drop due to an update, it's likely that the update which is causing your iPhone to drain more battery temporarily, will make you charge more often and drop the health. But it won't necessarily be a whole percent drop, it can be a fraction of a drop as battery health will round down any tenth.

When the tasks are complete which usually takes 36-72 hours, but can take longer if you have more data and spend less time on the charge and on a strong Wi-Fi connection.

You will also see app updates that may have a negative effect on your battery performance. App updates happen in the background by default and users rarely even know that the app was updated, unless they pay attention to the small blue dot next to the app after it has been updated. It is easy to misinterpret a change to an iOS update that requires action on your part to complete and you see the confirmation screen after it has been updated.

Some developers such as Meta have been updating their apps as much as 10 times in just the last month attempting to fix bugs so it is difficult to determine if an issue is due to the app update or iOS update. Check the apps using your Battery at Settings > Battery and scroll down to review the graph showing rate of drop and the top apps noted below the graph that are consuming the battery. Some apps will have background processes that will consume the battery even when you are not using the app. Background App Refresh has no effect on these operations, as that setting is only for a UI refresh.

As Zachyy said, every iOS update will cause your phone to re-index its files and will increase battery usage during that time. We see these same type of posts after every update, then they go away after the indexing stops. It has been that way for every update in the past and you can expect it again on the next iOS update.

Smacrae1 wrote:

Thanks for all your replies the forced restart hasn’t fixed it. Anyway why in this day and age does it need that? I think there is a problem with 18 I suppose Apple will stick their head in the sand and ignore it until they figure out a fix.

it's very hard for Apple to "figure out a fix" for an issue that doesn't affect most users. iOS 18.5 has caused absolutely no battery drain on either of our iPhones. But with every iOS update which has come out that I can remember over the years, there is always a small fraction of people who are convinced the update caused battery drain on their phone. I'm not suggesting you don't have battery drain. I'm suggesting it's not necessary a result of an update.

Here's what I would do if I were you, since the forced restart didn't do anything. I'd back up my iPhone, then restore my iPhone from backup. Preferably using a computer as using a computer will install a fresh copy of iOS on your phone.

See how to do this here --> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Smacrae1 wrote:

It was updated mid May and we are now the 9th of June... thats alot of indexing so Im sorry that explanation does work.

Then it's possible the battery drain is not coming from the update. Do you have any Meta apps as Mac Jim ID stated? Those are big battery drainers. Please go to Settings > Battery, and post a screenshot of your past 24 hour usage by percent and time.

The last 24 hours is the best gauge instead of the last 10 days and the battery graph along with any other information provided by the top 5 apps. Some will note background processes that continue to use your battery when in the background and others will show Notification when those are contributing to the battery drain. Home & Lock Screen usage is usually due to file indexing or object detection analysis on your photos. This is usual after every update, but by now should have completed long ago for you as it normally only takes about a week as long as you are not using Low Power Mode. That is where the last 24 hours will be more relevant.

I assume you are not currently using any beta software that is available now to developers, and you certainly would not want to install any beta on a primary device.

Hopefully the battery will solve the problem for you. If that does not work you are going to have to look closer at your app and provide a screenshot of the graph with the battery usage of the top 5 apps over the last 24 hours.

Not sure why users don't think apps are ever the cause of battery draining, it was just seen last week that the Weather Channel app update included a bug that failed to release location services and drained the battery. The developer updated the app and it is now working correctly.

With the millions of devices currently using iOS 18, you would see the issue on every device. The difference among those devices are the apps that are installed on them.

Did you force restart your iPhone after you updated? This is something I do after EVERY iOS update and I have never had an issue afterwards. Do this on your iPhone and see if things improve --> Force restart iPhone - Apple Support

ravenby wrote:

all versions of iOS after 18.3 greatly reduced battery life. things got really bad on ios 18.5. I don't want to use such a device. it feels like any update breaks the iphone. there is no desire to install updates. It's like you're not fixing and fixing bugs, but adding new ones. everything is very bad so far. I'm thinking of changing the entire apple ecosystem to competitors (for the first time since 2007.

You are welcome to choose any device you wish. Doing so won't matter to anyone here on this user to user only forum, which no one from Apple participates or will see your comment.

iOS updates DON'T cause battery drain. If iOS updates universally caused battery drain, this forum would be literally littered with people complaining, yet it's not. But that doesn't mean something isn't draining your battery. What you need to do is determine what is draining YOUR battery. One way to see that is to open Settings > Battery and look at the list of things which are using the most charge. From there you can certainly force close them.

When was the last time you Force Restarted your iPhone? A Forced Restart is recommended after iOS updates. Perhaps this is why I have never experienced any battery drain after any iOS update in all the years I've owed iPhones. This is how to do a Forced Restart --> Force restart iPhone - Apple Support

sitka88 wrote:

While this can describe the routine issue for any major iOS upgrade, it doesn’t address the actual issue that’s occurred with iOS 18. If you look around and read user experiences, you’ll see that this is a larger issue with the iOS, and it lasts more than a day or two.

If you look around you will also see the same thing is said with every iOS update, so there is nothing special with iOS 18. In fact you can also expect to see the same posts with the next update, it is very predicable and has been true for iOS 17, iOS 16, iOS 15, etc.

In most cases, it will take a week on average, depending on your Photo Library size. If you still experience a problem, then post a screenshot as recommended for the last 24 hours showing the green graph along with the top 5 apps. It is the apps causing the problem at that point. If you do not want to post the screenshot, Factory Reset the iPhone, without restoring the backup, using a computer to restore iOS and you can compare the results yourself. It really is that simple and by backing up to the computer before the Factory Reset, you can always restore your data, otherwise you would want to turn off iCloud backups while you test to prevent your data from being overwritten.

Doing nothing and continuing to believe it is iOS 18 that is just about a year old now and currently installed on millions of devices is not going to get you anywhere.

It would be unusual for your top consuming app to only be showing 10% when viewing the previous 24 hours. If that is the case, then post a screenshot that includes the graph along with those top apps listed. I would also perform the Force Restart as suggested by lobsterghost1.

Smacrae1 wrote:

Not sure what this is going to tell you down to 19% at 7.16 pm and don’t blame it on someone else other than Apple. A full reset really?

If you think it is iOS, then a reset without restoring from a backup will show you that is not the case.

The screenshot of the graph and the top apps consuming the battery will show you the cause. The choice is yours how you want to proceed.

Google has already blamed Meta for the poor battery usage on Android devices and Meta has committed to fixing the problem, so we shall see if that update will fix their problems and if they do the same on the iPhone. Yes, the apps will cause poor battery performance and Apple gives you the tools to identify them. It is what you are going to do about it that will be the resolution.

Then post a screenshot of your graph including the top apps using the last 24 hours option for viewing the data.

iOS 18.5 consumes a lot of power and generates a lot of heat. This is not your illusion, but a real problem. However, iOS 18.5 fixes 30 well-known high-risk vulnerabilities and is the safest system you can use. For safety, you can only compromise with the power consumption and wait for 18.6.

Home and Lock Screen isn’t necessarily all Apple, third-party widgets and notifications are included in this. Mail also isn’t all Apple and can include all inbound communication to you across your email providers.